Yeah that sounds about right. I paid a Ford dealer a little over $900 for parts and labor do to a gear swap.
I've heard of private shops doing it for less but couldn't find any in my area.
Would not do again btw. My rear end made noise and the performance difference between the gears was disappointing. I actually ended up missing the longer gears once I got a good tune.
If it made noise, they did it wrong. Putting a Ford gearset into a Ford rearend should not generate any additional noise that the previous gearset didnt have.
2011 Mustang GT M6 3.31s
Matt HONEYCUTT Tune, Lethal Off-Road X, GT500 axlebacks, J&M LCAs, UPR UCA, Whiteline LCA relocation brackets, Eibach Pro-Kit Springs, Koni STR.T shocks/struts, GT500 strut mounts, SR Strut Tower Brace
Best 1/4 E/T (05/18/14 MIR - no tune, X-pipe, or UCA): 12.920 @ 109.40 mph (2.059 60ft)